The Influence Of Galvanizing Method And Thickness Of Galvanized Steel Sheet On Spot WeldingAug 29, 2017

According to the different galvanization process, galvanized steel plate can be divided into galvanized steel plate and hot-dip galvanized steel plate, there is a kind of alloying zinc-coated steel plate, is in hot-dip zinc after thermal insulation at 450oC above the alloying treatment. Compared to these three, the plating zinc plate is thin, the weldability is relatively good, but the cost is high; hot-dip galvanized steel plate coating thickness, good corrosion resistance, but poor weldability; the weldability of alloying zinc-coated steel sheet was improved by relative hot-dip galvanized steel plate, and the hot galvanizing plate had better weldability than the galvanized sheet under the same thickness of Zn layer.Galvanized Steel Sheet

The thickness of the zinc layer is very small for the steel plate, but the effect on the weldability is very large. It is generally thought that with the increase of zinc layer thickness, the required welding current is larger, but Cheng is quite equal to [4] through the test comparison, it is found that in a certain coating thickness, the thicker the zinc layer, the required current is greater, but when the zinc layer reaches a certain thickness, the required current is reduced. The American Institute of Metals, the editor of the relevant information [5] is clearly proposed, when the thickness of galvanized steel sheet is increased (Zn layer thickness is 0.005~0.025mm range), the weldability is reduced, but the zinc layer thickness is 1. When more than 52mm, the weldability is not affected by the thickness of the coating.Galvanized Steel Sheet

In the domestic and foreign automobile body manufacture, the electroplating zinc plate coating thickness is generally ~90g/m2 (0.003~0.013mm), the coating thickness of hot-dip galvanized steel sheet is 40~180g/m2 (0.006~0.025mm), it can be seen that the spot welding of galvanized steel plate needs reasonable selection of process parameters to ensure welding quality. However, the author of the factory practice confirmed that, despite the existence of zinc layer, as long as the selection of appropriate equipment, technology, galvanized steel plate resistance spot welding quality can meet the technical requirements of the body manufacturing. Therefore, galvanized steel plate itself or zinc coating thickness, not affect the quality of the car-body spot welding determine the factors.Galvanized Steel Sheet